Door-key lock



May 4, 1948.

L. C. HELMES DOOR-KEY LOCK Filed Aug. 13', 1946 "ltzfl Patented May 4,1948 Ni'iED STATES PATT FFICE The invention aims to provide anexceptional simple and inexpensive, easily attached and effective devicefor holding the lock-actuating key of a door in door-locked position,preventing the key from being turned from the outside of the door, orpushed from the key-hole to make possible the insertion of another keyor a pick.

Figure 1 of the accompanying drawing is an inner side elevation showingthe device applied, the shank of the key being shown in section.

Fig. 2 is a disassembled perspective view of the attachment, with theexception of the four screws hereinafter described.

In the drawing, the numeral 3 designates a portion of a door and 4 hasreference to a part of the frame carrying the customary keeper 5 for thebolt 6 of the door lock, said bolt being projectable and retractable bymeans of the usual beard l on one end of the key shank 8. 9 denotes akey-hole in a door plate Ill, through which the key is inserted andremoved, and H has reference to one of the usual door knobs.

A clamp I2 is provided to be tightly secured to the key shank 8, saidclamp having a lug l3 which projects upwardly when the key occupies itsdoor-locked position. A vertically swingable latch arm Hi is provided,to be pivotally mounted on the door, the lower edge of said latch armhaving a notch It to engage the lug l3, thereby holding the key againstrotation until said latch arm is lifted by hand. One end of this latcharm is horizontally oliset as shown at I6 and is formed with an openingI! to receive a screw- I8 by means of which the arm may be pivotallymounted on the door 3. A suitable guide I9 is employed for the other endof the latch arm l4, said guide having a slot 20 in which said arm isvertically movable. This guide is formed with an attaching foot 2|having an opening 22 through which to insert a screw 23 for securing theguide to the door 3.

The clamp l2 includes two clamping blocks 24 and 25 for disposition atopposite sides of the key shank, saidblocks having seats 26 and 21respectively to engage said shank. The side of the block 24 remote fromthe block 25 is formed with a right angular notch 28 which opens throughone end of said block 24, and the inner end wall 29 of said notchconstitutes a shoulder which abuts the inner end of an attaching foot 30with which the lug I8 is provided. One clamping screw 3i extends throughthe foot 30 and through one end of the blocks 24 and 25, and v anotherclamping screw 32 extends through the other end of said clamping blocks.When these screws are tightened, the lug I3 is securely attached to theclamp and the two sections of this clamp are tightly drawn against thekey shank 8 to secure the clamp solidly to the key.

The attachment may be quickly and easily applied to any door and its keyand will constitute an effective and durable means for holding the keyin door-locked position. The arm M is held against downward swingingbeyond the required extent by means of the guide l9, and will,therefore, stand in readiness for use whenever the door is to be locked.As soon as the key is turned to door-locking position, the lug l3 isengaged by the notch l5 and thus held so that it cannot be turned fromthe outside of the door and cannot be pushed from the lock.

While excellent results may be obtained from the details disclosed, andthey are preferably followed, minor variations may of course be made,within the scope of the invention as claimed.

I claim:

1. An attachment for holding a door key in locked position, comprisingtwo clamping blocks for disposition at opposite sides of the key shank,said blocks having seats to engage said shank, clamping screws connectinsaid clamping blocks for clamping them tightly on said shank, a lugProjecting from one of said blocks, a latch cooperable with said lug tohold the key against rotation, and means for mounting said latch on thedoor.

2. A structure as specified in claim 1; said lug having an attachingfoot through which one of said screws extend-s to secure said lug tosaid one of said blocks, this block being provided with a shoulderabutting said foot and holding it against turning upon said screw.

LESLIE C. HELME'S.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 48,602 Tempest July 4, 1865756,064 Sherman Mar. 29, 1904

